Is CVE-2021-3996 actively exploited?

CVE-2021-3996 has no public evidence of in-the-wild exploitation as of 2024-11-21.

What is the CVSS score for CVE-2021-3996?

CVE-2021-3996 has a CVSS score of 5.5 (MEDIUM severity). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

How do I patch CVE-2021-3996?

Patch guidance is available from kernel security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-3996.

CVE-2021-3996 - remediation guidance & executive summary

Q: Which products are affected by CVE-2021-3996?

2 products: kernel util-linux, fedoraproject fedora.

Description

A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users' filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.

CVSS Metrics

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector: local
Complexity: low
Privileges: low
User Action: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high
Weaknesses: CWE-552 CWE-552

Metadata

Primary Vendor: KERNEL
Published: 8/23/2022
Last Modified: 11/21/2024
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

kernel : util-linuxfedoraproject : fedora

Remediation Guidance

Executive Summary

Cite this page

CVE-2021-3996. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2021-3996

View on NIST NVD

CVE-2021-3996 vulnerability